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1. 1. Derive the expression for Work done of a reciprocating air compressor without clearance
volume.
2. A single stage single acting air compressor as a cylinder a bore of 175mm and stroke of 225mm.
The compressor sucks air at 100KN/m2
and 27°C and delivers at 8bar. Find the power required to drive a
compressor, if its speed is 120rpm also calculate a mass air compressed per minute and delivery
temperature. The compression follows the law pV1.3
=C. (Pg.No: 4.14)
3. An air compressor receives air at 1.2bar and 18°C. It compressor the air to 8bar. Calculate the
heat removed and work done per m3 of air taken in the cylinder when the air is compressed
adiabatically, isothermally and polytropically (PV1.25=C). (Pg.No: 4.17)
1. Derive the expression for Work done and volumetric efficiency of a reciprocating air compressor
with clearance volume.
2. A single cylinder acting acting reciprocating air compressor with a bore of 12cm and stroke of
16cm runs at 410rpm. At the beginning of compression, the pressure and temperature in the
cylinder are 0.98bar and 40°C. The delivery pressure is 6bar. The index of compression is 1.32. the
clearance is 6% of stroke volume. Determine the volume of air delivered referred to 1bar and 20C.
What is the compressor power required? (Pg.No: 4.36)
3. A single stage single acting reciprocating air compressor takes in 17m3
/min at suction conditions
of 100 kPa and 25°C. The delivery pressure is 700kPa. The clearance volume is 6% of swept
volume. The compression and expansion follows the law pV1.3
= Constant the speed of the
compressor is 600 rpm. Stroke to bore ratio is 1. Invent (find) the power required to drive the
compressor and Cylinder dimensions.
4. A single acting 14cm x 10cm reciprocating compressor is operating at p1=1bar,T1=20C,p2=6bar
and T2=180C. The speed of compressor is 1200 rpm and the shaft power is 6.25kW. if the mass of
air delivered is 1.7kg/min. Calculate the actual volumetric efficiency, indicated power, isothermal
efficiency, mechanical efficiency and overall efficiency. (P.N:4.69)
5. A single stage acting air compressor delivers 0.6kg of air per minute at 6bar. The temperature
and pressure at the end of suction stroke are 90C and 1bar. The bore and stroke of the
compressor are 100mm and 150mm respectively. The clearance is 3% of the swept volume.
Assuming the index of compression and expansion to be 1.3, Find (i) the volumetric efficiency of
the compressor and (ii) the power required if the mechanical efficiency is 85% and speed of the
compressor. (Pg.No: 4.75)

2. 1. Explain the construction and working of Multi stage compressor and discuss the perfect and
imperfect inter cooling with neat a sketch. And drive minimum work required for a two stage
reciprocating air.
2. A two stage single acting reciprocating air compressor takes 6m3
of air at 1.1bar and 23°C and
compress in to 20bar the intermediate receiver cools the air to 25°C and 8.5bar pressure the law
of compression is pv1.35=C. calculate the work dine. (Pg.No: 4.50)
3.A two-stage single acting reciprocating air compressor with perfect intercooling with a suction
pressure of 1bar and temperature of 25°C and the final pressure is 5bar. Both compression and
expansion follows the alw PV1.3=C. find per kg of air (i) work donw and (ii) the mass of water
necessary for abstracting the heat in the inter cooler, if the temperature rise of the cooling water
is 30°C. (Pg.No: 4.53)
4. A multistage air compressor is to be designed to evaluate the pressure from 1bar to 120bar.
Such that the single stage pressure ratio is not to be exceeded 4. Find (a) number of stages, (b)
exact stage pressure ratio and (c) intermediate pressure. (Pg.No: 4.61)
5. A two stage double acting air compressor operating at 200rpm takes in air at 1.013bar and 27°C.
The size of LP cylinder is 355 X 375mm, the stroke of HP cylinder is the same as LP cylinder and the
clearance of both the cylinder is 4%. The air passes through the intercooler so that it enters HP
cylinder at 27°C and 3.850bar, finally it is discharged from the compressor at 15.4bar. The values
of n for both cylinders are 1.25. Cp=1.0035kJ/kgK and R=0.28kJ/kgK. Calculate:
(i) The heat rejected in the intercooler. (ii) The diameter of HP cylinder and (iii) The power
required to drive HP cylinder. (Pg.No:4.100)
6. A three-stage air-compressor delivers 5.2 m3
of free air per minute. The suction pressure and
Temperature are 1 bar and 30°C. The ambient pressure and temperature are 1.03 bar and 20°C.
The air is cooled to 30°C after each stage of compression. The delivery pressure of the compressor
is 150bar. The RPM of the compressor is 300. The clearances of LP, I.P and H.P cylinders are 5% of
the respective strokes. The index of compression and re expansion in all stages is 1.35. Neglecting
pressure losses, Calculate the B.P of the motor required to run the compressor if the mechanical
efficiency is 80% (Pg.No: 4.100)
7. A single –acting two stage air compressor deals with 4m3/min of air at 1.013bar and 15°C with a
speed of 250rpm. The delivery pressure is 80bar. Assuming the complete inter cooling, find the
minimum power required by the compressor and the bore and stroke of the compressor. Assume
a piston speed of 3m/s, mechanical efficiency of 75% and volumetric efficiency of 80% per stage.
Assume the polytrophic index of compression in both the stage to be n=1.25 and neglect
clearance. (Pg.No:4.94)